Lining for tube-mills and ball-mills.



F. G. BROWN.

LINING FOR TUBE MILLS AND BALL MILLS.

Ar'PLioA'nou FILED APB.15, 1908.

991,421 Patented May 2,1911.

To all whom it may concern:

rmannnzcx carer] BROWN,

OF WAIHI, NEW ZE-ALAND.

LINING FOR TUBE-MILLS AND BALL-MILLS.

Specification of Letters Patent.

Patented M y 2, 1911.

Application filed April 15, 190a Serial No. 427,269.

Be it known that I, FREDERICK CAPEL BROWN, a subject of His Majesty the King of the United Kingdom of Great Britain and Ireland, resident of VVaihi, in the provincial district of Auckland and Dominion of New Zealand, mine superintendent, have invented an Improved Lining for Tube-Mills and Ball-Mills and Similar Grinding and -Pulverizing Machines, of which the followin is a specification.

his invention relates to new and useful improvements in ball mills for pulverizing material by trituration wherein the mill cylinder is lined internallywith slabs having longitudinally ribbed working faces.

One object of the invention is to improve the liner construction by forming the ribs thereof with working faces inclined in wardly in the direction of rotation of the mill, in order that the cascading action of the balls may be rendered more efficient.

A further object of the invention is the provision of a liner consistin of a series of metal slabs which are each of such construction that the efiicient life of the liner is eatly prolonged, this advantage resulting rom the fact that each slab is of increased thickness'throughout a longitudinal central portion, which portion is of greater thickness than the portions of the slab on either side thereof, is equidistant from the side edges of the slabs and from the scams or joints coincident with said side edges, is-

subject to greater wear than the other portions of the slab and has greater wear resisting property. The slabs are themselves readily renewable and are preferably of a construction which provides for the ready renewal of parts or sections thereof.

Embodiments of the invention are illustrated by way of example in the accompanying drawings, wherein Figure 1 is an elevation of an end of the tube mill, showing the manner in which the slabs and their adjuncts are fitted therein; Fig. 2 is a plan view 'of one of the slabs showing more particularly the central reinforcing bar thereon, and the recesses in the edges of the slab which partially surround the securing bolts; Fig. 3 is a plan view of a bar of iron or other suitable material, which is constructed with enlargements at suitable intervals for a purpose to be described; Fig. 4 is a cross sectional view of the bar shown in Fig. 3; Fig. 5 is a cross sectional view of a modified form of bar, intended for the same purpose as the bar shown in Fig. 3; Fig. 6 is an enlargedcross sectional view of one form of slab construc tion; Fig. 7 is a cross sectional view of an alternative slab construction; and'Fig. 8 is a cross sectional view of a further alternative slab construction.

Similar characters of reference designate corresponding parts throughout the several views.

Referring to Fig. 1, which shows essen t-ially the manner in which the slabs are fastened, the letter A designates a tubeor similar mill which is' fitted with slabs extending longitudinally thereof. These slabs are constructed with central longitudinal portions of increased thickness, for a purpose which will presently appear. In the arrangement shown in Fig. 1, theslabs designated by the numeral 1, each have a central longitudinal rib, as 2, upon which is removably fitted a wear bar, as 3, the working faces of the slabs on each side of the rib being flat. The bar 3 has its working face inclined inwardly in the direction of rotation of the mill, as is indicated by the arrow B, and its use upon the rib 2, though preferred, is optional. The wear bar 3 has an L-shaped cross section, in order that it may be more readily and accurately centered upon the rib to which it is fitted, the flange of said wear bar .fitting against a side face of the rib and the body portion of, said wear bar entirely covering tl1e plan face of the rib.

Fig. 6 is an enlarged cross sectional view of the particular form of slab shown in Fig. 1, as applied to the mill cylinder.

Referring to Fig. 7, wherein an alternative form of slab is illustrated, the central rib shown in Figs. 1 and 6, is not employed. Instead of using this construction, the thickness of the slab is gradually increased from each of its longitudinal side edges or from lines inwardly thereof, to a median line at which the greatest wear occurs, oppositely and inwardly inclined wearing faces, 215.5, and a central longitudinal apex, as 6, bein thus afforded. The alternative form 0 slab shown in Fig. 8, is of uniform thick;

ncss except at its central portion where Jg.

suitable intervals with recesses or halfholes, as 8, the recesses 8 of one slab registering with the correspondingly located recesses of an adjacent slab. The fastening bolts by which the slabs are connected to the cylindrical body of the .mill, may be passed through these recesses, as indicated in Fig. 1. In; connection with the fastening of the slabs, it is preferred to employ longitudinal bar-ii, as 10, which not only are of advantage in providing for a more efiicient fastening of the slabs but also may serve as cascading .bars, in which function they correspond to the central longitudinal ribs above referred to. In Figs. 3 and 4', the bar 10 is shown as of solid construction and is provided at intervals with openings, as 11, through which the fastening bolts 12, connecting the slabs and the mill cylincler, pass. Adjacentthe openings 11, the bar 10 may, if desired, be provided with enlargements, as 13, by reason of which the provision of the openings 11 'will notweakcn the bar.

' Instead of making the bars 10 of solid construction, as shown in Fig. 4, I may make them of sectional construction, as shown in Figs. 1 and 5, in which case the bar comprising a body section as 10 and a wearbar section, '14, which is fitted upon the inner face of the body section and is held by the securing bolts 12. The bar 14 corresponds in function to the wear bars 3 above referred 'to, and, like the latter, is readily renewable. In Fig. 5,.the wear bar 14 shown as having a flat wearing face whereas in Fig. l the wear bar 14. is shown as having an inclined wearing face, and similar in all respects to the bars 3 shown in the same figure. The inclined wearing faces a re preferred, th ugh if circumstances or conditions of use slmld render it desirable, the barsilor 14 may be formed with flat working faces. If for any reason, the use of either of the wear bars is not desired, the faces of the ribs or bars 10 as the case may be will then become-working faces and maybe made flat or inclined, in the manner stated. it will. also be understood. that wear bars may be applied to the ribs of the slabs shown in Figs. 7 and 8, if

desired.

To provide for the ready assemblage of the renewable. wear bars, the latter are preferably of an L-shaped cross section, whereby against .the central portions. It requires a.

considerable period 'of'timc" for the balls to wear down the reinforced central portions and in the meantime the slab is not broken or otherwise rendered useless. It is thus assured that the slab shall have an efficient life consistent with its greatest thickness.

The arrangement is also of advantage in a ing the slabs securely in position, have the further advantage of preventing undue wear caused by'the sliding motion of the :cbblcs or balls on the lining of the mill that by inclining the faces of these bars in the manner indicated, the pebbles or balls are lifted higher at each revolution of the mill, thus increasing the grinding or pulverizing efliciency of the mill; and that by reason of the thickness of the slabs being proportioned as described, the loss of metal and worn-out liners, is reduced. This method of running a mill improves the work done by the mill by preventing the slipping of the pebbles or balls on the lining of the mill and the grinding etliciency of the mill is increased, due to the lifting action of the bars on the pebbles or balls. Cconomy is also maintained by this action in the wear of the liners.

The slabs and other parts are shown as only fitted wilhina portion of the inside of the mill, but in practice they will preferably be titled all around the inside and their form may be varied according to circumstances.

llaving fully described my invention what T desire to claim and secure by LcttersfPatcut is:-

1. A. tube will liner comprising a series of longitudinally disposed slabs removably as sembled in the mill structure and having longitudiiml central portions of increased 'thickness, and wear bars secured to said central portions and projecting inwardly with respect to the mill. f

2. A tube mill liner comprising a series of longitudinally arranged slabs removably assembled in the mill and having longitu-' dinal central portions of increased thickness,

and longitudinally disposed wear bars 'arranged on said central portions andhaving their working faces transversely inclined in the directlon of rotation of the Ind].

3. A tube mill liner comprising a plurality of longitudinally assembled slabs, attachment bars overlapping" the adjacent slabs and projecting inwardly with respect thereto, means for attaching the bars to the mill structure, wear bars removably secure( .to the said attachment bars and extending longitlnli'nally centrally disposed thereof, said slabs having longitudinal wear I'lbS integral therewith and bars removably attached to said ribs and extending longitudinally thereof.

4. A tube mill liner comprising a series of removablyfitted longitudinally disposed metal slabs, each of which has its longitudinal central portion of gieater thickness than the portions on either side thereof, in combination with longitudinal inwardly rojecting bars rcmovablysecnred in the mi 1 a ong lines midway between the central portions of adjacent slabs.

5. A tube mill liner comprising a series of longitudinally disposed metal slabs, each of which has its longitudinal central portion of greater thickness than the portions on either side thereof, in combination with longitudinal inwardly projecting fastening bars overlying portions of the slabs on each side thereof.

6. A tube mill liner comprising a series of longitudinally disposed metal slabs each of which has its longitudinal central portion of greater thickness than the portions on either side thereof, in combination with longitudinal inwardly projecting bars removably secured in the mill along lines midway between the central portions of adjacent slabs and longitudinally disposed-wear bars fitted upon said first named bars.

7. A tube mill liner comprising a series of longitudinally disposed metal slabs, each of which has its longitudinal central portion of greater thickness than the portions on either side thereof, in combination with longitudinal inwardly p 'ecting fnsteninF bars overlying portions oi the slabs on eac 1 side thereof and longitudinally disposed gear bars reinovably fitted to said fastening ars.

8. A tube mill liner comprising a series of removablj; fitted longitudinally disposed metal sla s assembled to provide an im )erforate. interior tube mill working sm' ace,

the slabs being characterized by longitudinall and centrallydisposed inwardly exten ing spaced ribs which have their working faces transversely and inwardly inclined with respect to the direction of rotation of the mill.

V FREDERICK CAPEL BBOVVN.

Witnesses:

GEORGE WILLIAM Basnn'r,

Hiram Mar Fromm. 

